1. Field of the Invention
This invention relates to foot pedals which are operated by human feet to rotate beaters to strike drum heads of bass drums provided in drum sets.
2. Prior Art
Conventionally, various kinds of foot pedals are proposed and used for drum sets. An example of the foot pedal is disclosed by the paper of Japanese Utility-Model Publication No. 58-43035. The foot pedal is designed in such a way that a foot board thereof is depressed by a human foot to rotate a beater, which strikes a drum head of a bass drum.
FIG. 4 is a perspective side view illustrating an example of the foot pedal for the drum set conventionally known. Herein, a foot pedal 1 provides a pedal frame 2 made of metal materials such as aluminum alloy. The pedal frame 2 is manufactured by the die casting technique. The pedal frame 2 contains a frame body 2A and two support members 2B. Herein, the support members 2B are formed as incorporative parts of the frame body 2A, wherein they are planted onto both ends of the frame body 2A respectively. A heel 3 is connected to the frame body 2A by means of a connection member 4. Clamp metal fittings 5 are fixed to an upper face of the frame body 2A. The clamp metal fittings 5 are provided to securely fix a clamping frame (or hoop; not shown) of a bass drum. Bearing portions 8 to which bearings 7 are attached are formed at upper end portions of the two support members 2B. Ends of a rotation shaft 6 are rotatably supported by the bearings 7. A rocker 9 is fixed to a center portion of the rotation shaft 6. A beater 10 which strikes (or beats) a drum head is connected to the rocker 9 by means of a beater rod 11. A first end of a step force transmission member 13 is fixed to the rocker 9. Now, a person steps on the foot board 12 or depresses it by his or her foot, so that step force is imparted to the foot pedal 12. The step force transmission member 13 is provided to transmit the step force of the foot board 12 to the beater 10. As the step force transmission member 13, it is possible to use the materials having plasticity such as leather and resin-treated band, for example. Instead of those materials, it is possible to use a timing belt, a chain and the like. The foot board 12 is formed in a flat-plate shape having an area which is sufficient for a person to put on the sole of his or her foot. A front end of the foot board 12 is connected to a second end of the step force transmission member 13, whilst a back end is rotatably connected to the heel 3. One end of the rotation shaft 6 is connected to an upper end of a return spring 14 by means of a cam plate 15. The return spring 14 gives restoration behavior to the foot board 12 so that the foot board 12 is lifted upwardly. A lower end of the return spring 14 is connected to a spring bearing member 16 which is fixed to one of the support members 2B.
When performing a step operation on the foot board 12 of the foot pedal 1 whose construction is described above in conjunction with FIG. 4, the step force transmission member 13 moves downwardly, so that the beater 10 rotates together with the rotation shaft 6. Thus, the beater 10 strikes the drum head of the bass drum. Herein, a maximum step angle by which the step board 12 rotatably moves in a downward direction is 15.degree. or so. After the striking, when step force is released from the foot board 12, the foot board 12 is lifted upwardly by spring force of the return spring 14. So, the foot board 12 is restored to an initial state shown in FIG. 4.
In the foot pedal 1 shown in FIG. 4, when the step force transmission member 13 is moved up and down by performing a step operation on the foot board 12, upward/downward force works at a center portion of the rotation shaft 6 so that the rotation shaft 6 is partially bent to form flexure. Accordingly, flexure occurs on the upper-end portions of the support members 2B. Thus, there is a problem that the rotation shaft 6 deviates in an axial direction. When such an axial deviation occurs on the rotation shaft 6, the rotation shaft 6 does not contact with the bearings 7 in an uniform manner; in other words, the rotation shaft 6 contacts with the bearings 7 in a biased manner. Such a biased contact which occurs between the rotation shaft 6 and the bearings 7 is not preferable for the drum set because it prevents the rotation shaft 6 from being placed in a smooth rotation, or it causes noise. To avoid such a disadvantage, it may be possible to increase rigidity of the rotation shaft 6 as well as rigidity of the support members 2B. However, such an increase of the rigidity causes an increase of weight of the drum set as a whole. So, there is another disadvantage that the drum set is hard to be brought by human power.